With the development of the fireworks technology, sizing agents are formed by mold pressing with hydraulic machinery, molds in recent years, combined fireworks produced by forming into one-piece at one time has been widely used in industries. Shapes of the combined fireworks after formed are similar to that of the traditional combined fireworks, which shapes are generally prism, cylinder and so on. Several tubular cavities are uniformly arranged on the body of the combined fireworks, structures and functions of the tubular cavities are similar to that of the single cylinders of the conventional combined fireworks, with the upper ports of the tubular cavities are open and the lower ports of the tubular cavities are closed, inner cylinders of fireworks and propellants are arranged in the tubular cavities. The structures of the combined fireworks with a transmission mode is different from the transmission fire leading structures on the side of the traditional combined fireworks, the combined fireworks adopts priming connection wire structures on the bottom thereof. The closed end of the tubular cavities are provided with priming holes passing through the bottom surface of the body, the bottom of the body is provided with leads connected the priming holes of bottom openings, the leads are connected with each priming hole, the propellants within the above-mentioned tubular cavities are ignited through priming holes. The process of molding slurries by means of hydraulic machines and molds can be found in the Chinese Patent Publication No. CN 101377395B, issued on Apr. 11, 2012, entitled “Mold pressing outer cylinder, elastic spherical housing of fireworks and making thereof”.
Combined fireworks with launching pits and multi-channel fireproof structures
However, we found in practice that this combined fireworks formed by mold pressing still has the following shortcomings: (1) the propellants are not concentrated in the tubular cavities, and the gunpowder is dispersed and not uniformly distributed at the bottom of the tubular cavities, the action area to the bottom is large when the propellants are lit, the acting force pushed the inner cylinders of fireworks upward is small, affecting the launch height of the inner cylinders of fireworks and the effect pieces thereof. (2) The inner cylinders of fireworks within the tubular cavities has an inaccurate location, and not easy to coincide with the axis of the tubular cavity, and several disadvantages such as deviation in right and left often occur, trajectory offset often occurs during launching due to the location of the lower part of the inner cylinders of fireworks is not limited, the firing effect of fireworks is affected and even including the safety thereof. (3) A closed end of the tubular cavities are provided with priming holes passing through the bottom surface of the tubular cavities of the existing combined fireworks formed by mold pressing, the bottom openings of the priming holes are located in the wiring grooves within which and between the bottom surface of the priming holes are provided with cutting grooves, the wiring grooves are sealed with glues to prevent the occurrence of crossfire. As disclosed in the authorized announcement No. CN102914223B, the date of authorized announcement on Jul. 31, 2013, entitled “Combined Fireworks Formed by Mold Pressing”, which is such structures adopted by the cutting grooves and sealed by glues to prevent crossfire. But in the practical application process, we found that structures adopted by the cutting grooves and sealed by glues to prevent crossfire are not stable and reliable, because the combination of the glues filling the cutting grooves with the cutting grooves is not stable, the situations such as glue falling off and cracking often occur due to carrying, moving or vibration in the production, transportation and discharging process, especially during the process of ignition for launching, under the dual role of high temperature and airflow impact generated by burning leads and propellants and glues appear softening and cracking, and the cutting grooves can not play the role of cutting off crossfire, resulting the gunpowder and inner cylinders of fireworks inside each
Combined fireworks with launching pits and multi-channel fireproof structures tubular cavity are not lit and launched according to the designed discharging procedure, the occurrence of the situation of two or more tubular cavities are almost simultaneously emitted, and the firing effect is completely destroyed.